As students head back to school, eBay is getting into mobile textbook sales with the launch of a a new iPhone app from Half.com, which eBay bought in 2000 for $350 million.

The Half.com iPhone app is also the first eBay buying application to integrate barcode scanning technology, which was implemented through the acquisition of RedLaser in June. The app allows users to scan the barcodes on items to find the best deals on textbooks, DVDs, books, video games and more, with discounts of up to 50 percent or more off the normal retail price. However, eBay says the majority of items sold on Half.com are textbooks.

The Half.com app includes access to 80 million active listings from more than 700,000 sellers. And you can also share deals via Facebook and Twitter. The app also includes a Buying Wizard feature that shows users results based on the criteria for item condition and seller feedback.

It’s no secret that eBay is making a big push into mobile e-commerce. eBay is on pace to reach a whopping $1.5 billion worth of goods sold via mobile phones in 2010. eBay’s primary iPhone app has seen 11 million downloads and the company also launched iPad and Android apps this year.